The present invention relates to an adjustable, functional and removable orthopedic corrector and, more particularly, to an improvement to conventional orthopedic correctors employed by orthodontists to correct what is referred to in the field of orthodontics as a Class II, Division 1, malocclusion. A Class II malocclusion is defined as a malposition of the maxillary and mandibular teeth so that the lower dental arch is posterior to the upper dental arch, resulting in loss of efficiency during the movements of the jaw that are essential for mastication. In a Class II, Division 1, malocclusion, the upper incisors are protruding.
Orthodontics is a specialty of dentistry dealing with the correction of positional irregularities of the teeth. These irregularities are often associated with a malpositioned lower jaw in relation to the maxillary dental arch. The lower jaw or mandible and concomitantly the mandibular dental arch, depending upon the class of malocclusion, is anterior or posterior to the maxillar arch.
The practice of orthodontics involves the procedures requiring, on the average, 24 to 30 months to complete, using fixed appliances commonly known as braces and somewhat less time using a conventional functional removable orthopedic appliance. In the case of the Class II, Division 1, malocclusion, most orthodontists that employ fixed appliances must resort to either extra oral force, intermaxillar elastics, or a combination of both, to effect a basal maxillo-mandibular change and thus eliminate the excessive overbite, overjet or apical base discrepancy. The orthodontist who uses the conventional removable functional appliances can eliminate the extra oral force or intermaxillary elastics by substituting neuromuscular activity. With a removable and functional orthopedic appliance, the entire mandible is moved forward, freeing the condyle in the temporal mandibular joint from any possible growth restrictions due to dominate retrusive muscular activity associated with the Class II, Division 1, malocclusion. This forward movement of the mandible is caused by a stretch reflex initiated by the introduction of the orthopedic appliance into a patient's mouth, which causes the muscles to pull the mandible in an anterior direction. The removable functional appliance is fitted to a patient's posterior maxillary teeth so that it is anchored in both a longitudinal and lateral direction by those teeth. The anterior portion of the appliance extends in an angular direction from the posterior portion of the appliance towards the back of the lower front teeth so that when the lower jaw is closed it is forced, due to the interdiction of the anterior portion of the appliance, to move to a position forward of the anterior portion of the appliance. The anterior portion of the appliance is designed so that it is forward of the posterior portion of the appliance to such a degree that the lower jaw must move forward of its pre-treatment position relative to the upper jaw. The appliance is held against the roof of the mouth by action of the tongue.
The present practice uses a series of two or more removable functional orthopedic appliances to correct a Class II, Division 1, malocclusion. As the treatment progresses and the mandible comes in closer alignment with the maxilla, the second or third of the series of functional removable appliances is used by the patient. Each successive appliance is elongated along an anterior-posterior medial line relative to the previously used appliance. With each successive appliance the mandible is repositioned more closely to a correctly aligned state relative to the maxilla. It would be desirable to be able to use a single appliance for the sake of economy. However, a single appliance would necessitate a design which would cause the mandible to be positioned at or near what is termed the construction bite at the onset of treatment. The construction bite is defined as the maximum forward movement of the mandible which the patient can self induce prior to treatment. Such abrupt and continuous forward movement of the mandible by the orthopedic appliance would result in discomfort to the patient and possible periodontal neucrosis and root resorption.
The present invention improves the conventional orthopedic appliance by removing the necessity of using two or more separate orthopedic appliances to treat a given patient. The present invention solves this problem by dividing the appliance into an anterior segment and posterior segment. The two segments are connected by two expansion screw assemblies.
The orthopedic appliance of the present invention is designed so that even when the posterior and anterior segments of the appliance are minimally expanded, the mandibular-maxilla position is changed from that which exists prior to treatment. As time progresses, the expansion screw assemblies are turned, separating the anterior and posterior segments of the appliance with resultant movement of the mandible more forward.
The orthopedic corrector of the present invention may also be outfitted with various orthodontic attachments such as a labial archwire. With the addition of various orthodontic attachments, the orthodontist can correct the Class II, Division 1, malocclusion and, in addition, induce the movement of individual teeth.